This study is to evaluate the performance of an implantable stimulator system designed to provide activation and control of the paralyzed upper extremity in high level spinal cord injury tetraplegic patients. First generation eight-channel implant receiver stimulators have been implanted in over 100 persons and has received premarket approval from the FDA. We have begun the evaluation of a more advanced, second generation, ten-channel implantable stimulator-telemeter (IST) with an implanted joint angle transducer (IJAT). The significance of this ten-channel stimulator enables more functions to be provided. The design and in-vivo evaluation of the IJAT and IST have been completed. Human trials are proceeding.